In the retail industry, the largest expenditures are typically the cost of the goods sold followed closely by the cost of labor expended. With particular regard to the retail grocery or supermarket industry, the impetus to reduce labor costs has focused on reducing or eliminating the amount of time required to handle and/or process the items or goods to be purchased by a customer. To this end, there have been a number of self-service checkout terminal concepts developed which attempt to substantially eliminate the need for a checkout clerk.
A self-service checkout terminal is a system which is operated by a customer without the aid of a checkout clerk. In such a system, the customer scans individual items for purchase across a scanner and then places the scanned item into a grocery bag, if desired. The customer then pays for his or her purchase either at the self-service checkout terminal if so equipped, or at a central payment area which is staffed by a store employee. Thus, a self-service checkout terminal permits a customer to select, itemize, and in some cases pay for his or her purchase without the assistance of the retailer's personnel.
A customer typically has little or no training in the operation of a self-service checkout terminal prior to his or her initial use of the checkout terminal. One concern that retailers have when evaluating a self-service checkout terminal is the level of supervision provided to inexperienced customers. Moreover, it is also known that some customers may have improper intentions when using a self-service checkout terminal. In traditional checkout systems, the clerk employed by the retailer to operate the checkout terminal provides a level of security against theft or other improprieties. However, in the case of a self-service checkout terminal, the terminal itself must provide the necessary security. Such security includes preventing a customer from either inadvertently or intentionally placing an item in a grocery container such as a grocery bag without scanning the item, or voiding one item from entry, but removing a second item of lesser value, or no item at all, from the grocery bag. Thus, another concern when evaluating a self-service checkout terminal is the level of security provided against illicit use of the self-service checkout terminal by customers.
Therefore, self-service checkout terminals have heretofore been designed with security systems which monitor operation of the self-service checkout terminal. For example, weight scales have been incorporated into self-service checkout terminals to monitor the manner in which a customer handles or otherwise processes items during operation of the self-service checkout terminal. In particular, self-service checkout terminals have heretofore been designed with a weight scale positioned so as to detect placement of items in or removal of items from a bagging area associated with the self-service checkout terminal (including a number of shelves around the bagging area).
In such security systems, a security software application is executed by a processing unit associated with the self-service checkout terminal in order to analyze or otherwise process output from the weight scale and the other terminal components of the security system. It is imperative that the security software application is provided with timely, accurate, stable weight values from the weight scale in order to properly determine when a security breach has occurred. Weight scales which are commonly used in retail applications are relatively sensitive to weight changes, and therefore can sometimes generate output signals indicative of weight changes when in fact no items have been placed in or removed from the bagging area. In particular, most modern, commercially available retail weight scales include a controller which can calculate and thereafter output weight values in a relatively short period of time (e.g. typically measured in milliseconds). Such fast weight value generation may undesirably produce “false alarms” if reported directly to the security software application of the self-service checkout terminal. In particular, many environmental conditions and sources of environmental vibration present in a retail store may lead to an increase or decrease in the measured weight value of the items in the bagging area without an item actually being placed in or removed from the bagging area. That is, the environmental vibration introduces noise into the signals representing the measured weight values. For example, if a customer bumps into the self-service checkout terminal, the weight scale may actually register a weight change which could cause the security software application to falsely conclude that a security breach has occurred. Moreover, it is known that the cycling of the retail store's air conditioning system can cause changes in the measured weight of the items in the bagging area if the self-service checkout terminal is positioned in a certain location relative to outlets associated with the air conditioning system. Further, environmental vibrations can be a problem when the supporting floor is not rigid enough to prevent bounce of the equipment.
The environmental vibration results in decreased precision or longer settling times for the bag scale system. As a result, the system may not correctly recognize the weight of the item on the scale, causing the system to falsely trigger a security alarm. In the extreme case, the system becomes unusable because the weight detected by the scale appears to continuously drift, thereby making it impossible for the system to measure actual weight.
What is needed therefore is an apparatus and method for operating a self-service checkout terminal which overcomes one or more of the above-mentioned drawbacks. What is particularly needed is a method and apparatus which provides timely, accurate, and stable weight measurements for use by a security software application associated with a self-service checkout terminal.